A vertical power MOSFET device usually has a source electrode formed of a source metal layer and a gate electrode formed of a gate metal layer disposed on a top surface of the semiconductor chip and a drain electrode formed of a drain metal layer on a bottom surface of the semiconductor chip. A bottom source power MOSFET chip having a source electrode on one surface and the gate electrode and the drain electrode on the other surface is preferred in applications such as stacked die co-package structure used in a DC-DC converter. In other applications, bottom source power MOSFET chip is required, for example, when the die paddle of a lead frame package is used as the ground electrode.